Multistage, axial flow, gas compressor



July 12, 1949. H. F. HAGEN 2,476,191

' MULTISTAGE, AXIAL FLOW, GAS COMPRESSOR Original Filed June 15, 1945 5 Sheets-Sheet l Inven?o2-. 6 2/6040 F. HAG

fifor eg H- F. HAGEN MULTISTAGE, AXIAL FLOW, GAS COMPRESSOR July 12, 1949.

3 Sheets-Sheet 2 a i w Original Filed June 15, 1945 Ihven 7hr.

i 1 E mu L I I LLJJU lllll July 12, 1949. F HAGEN $476,191

MULTISTAGE, AXIAL FLOW, GAS COMPRESSOR Original Filed June 15,1945 5 Sh eetsSheet 3 117062? 707*. 6 92040 F. HAGE V flii'vrney.

Patented July 12, 1949 -RIULTISTAGE, FLOW, GAS QOMPRESSOR Harold F. *Ha'gen, Norwell, Mass, assignor, by

meme assignments,

-Corpcraticn,=- -a;corporation of Rennsy-lvania zorjginal 4. application June 15 .1945, Serial .No. ..599;704. .LDiwidediand this application'Decemuberfll, 1947,?Serial No. 791,101

'iZDlaiims. 1

This invention "relates "to :"supercharges, and relates more-particularly to the-superchargers "formaintaining desired air pressures in tbe cabins of aircraft flying at highaltitudes.

This application is" adivis'ion cfmy "co-pending application, Serial -No."-599,704 filed June 15, 194-5. =-Atan altitude of"40;'000' 'above'sea level, the atmosphere pressure is' only about Zillpcunds per square inch absolute. "Iris-desired to increase this pressure "to "about 936 pounds per square inch witliirrthe--calcinofv ani-airplanefiyin'g that altitude. 'L'The limitations "of "space and weight prevent the use o'f large size equipment so that it -is "necessary that a relatively small,

high speed -supercharger with 'a large number of blower stages be "used. "This invention "pre vi'des such a supercharger.

In one-embcdiment-of the 'inventioripa ten stage supercharger has axialflow, blower wheels designed to revolve '-at 42000 revolutions per minute.

Due-to problems involving the'driveyit'is clesired tooperate'th'e supercharger-at constantspeed at all altitudes although itsiull-capacl-ty is not needed -below 40;000". If thesupercharger is operated at fullcapacity-at'sea level where the the temperatureof'the'ainwill rise irr-the supercharger to about-450F 'tcohot to discharge into the cabin. *Furtherm'ore while the "driving charger operated at full capacity will be about It'not' being desired to increase thejpressure in the cabin much above the atmospheric pres- 'sure ahsea; level, the pressure increase-provided must be r reduced: to "a fraction =ofwa pound, just suiileient for' providing ventilation, at sea level, and reduced in less degree at altitudes "below 40,000. The pressure provided -='could 'be---reduced by dampering, but this would no't resnlt in the desired reduction in air temperature, nori in the-desired saving" in" power.

A power of 'this' invention resides in the -use of spin vanes :ofth'e type-disclosed generally'in the H. F; Hagen; USS; Pa-tents Nosi13465863 and 1,989,413; the :vanes' :being provided in the inlets "of alkofthe later stage blower wheels. "With'the vanes adjusted to :positions w-of maximum spin, there: is substantially noair pressure rise. With the vanes: adjusted =towide :open positions, they straighten out the spinning --z'a,irancl the super- :chargeroperates at full capacity. "The-vanes are adjusted by a suitable barometric COIItrPOPtQfpiO- vide the desiredair pressure at'every' altitude.

"Not" only-do the 'vanes provide power reductions which conform to the pressure reducticnsfbut 5 the-temperatures of the delivered air are reduced as the air pressures are reduced. -=At -40,000 altitude; the-outside temperature may be 60 F. s0 that-the temperaturecf the delivered air 'will'be el-bout 1'90 F'.--which is not too hot to discharge into the -cabin.

As is known, it is essential *for continuity of '--flow,'---to--have the same mass of air handled by every blower wheel of a multi-stage1ai1'=-comcpressor. "The: air density increases in downstrearns= stages due-to temperatureaand: pressure "increases, and-as the density increases, the vclume decreases. It is the general practicei to'ide signsthe'zdovmstreamtblowerxwheelsto handle le zairrvolumes than-atheupstream :wheels. in the past: this .=:':h'a;s i'tbeen accomplished .;by eproviding dffierentlyfiesignedblower wheielsionevery-stage,

:lthus requiringea separate die-forueach wheel. .eAndther: feature of: this .inventionresides. inyusing asimilarilyadesigned ;a nd,::.constructed wheels for Zm-euery staga-a'andrby cutting. off 1. the; outer ends ofaithe blades of the-downstream; stages for prim :gressively decreasing thed'ownstreambladerareas. Likewise; all. spin 'vanes. are made, the same may, the; downstream wanes having theimends cut off 30 toryprovidingvane areas reduced conformablg: thei-bladelareas .of -the.-wheels,.inathe inlets ohwhich theyare placed. :Not. only is. thecost rc- .duced bynsing-a singleidie for everywheel, and .a. single die for alll spin r vanes; but the gaefilciencies .are..,maintained ..uniform since axial velocity throueheach wheel is uniform.

"Due to the large pressure increase when the supercharger. isaoperating. at full. capacity, there considerable endfthrnst upon. its hearings, in addire'ctiom opposite Jtatha't of'the .alr lfiow .Z'throughthe supercharger. The bearings, con-- sidering "the fact'that .thev speed of rotation of the supercharger shaft is sohigh, could-not ,be expected L to stand. up :und'er "this thrust. An-

other feature; ofiithis invention'iis that the end :;thrust isneutralizediby; applyingairpressure" at :the' output sideof the supercharger to a member carried by the "revolving shaft.

Due to the high rotative speedandtin-3* low --'pressure "around the "upstream bearing of "the supercharger, lubricating oil *tends" 'to leak from the bearing into the air stream enter ing *the supercharger-and to be! discharged into the cabin with the compressed air. -"Ancther feature of this invention resides in the provisicn' of a? fan-'--wheel 3 on the upstream end of the supercharger shaft, the inlet of this wheel connecting with the interior of the upstream bearing, whereby upon ro tation of the shaft, the fan wheel draws air through the hearing which air entrains the oil thrown out from the bearing and delivers entrained oil to a point exterior the supercharger.

Objects of the invention are to provide an efficient, multi-stage supercharger having flow wheels, and to control the output of the supercharger with spin vanes in the inlets of blower wheels of same.

Another object of the invention is to oppose the end thrust in a supercharger caused by the movement of air therethrough, by the applica tion of air pressure at the outlet of the supercharger.

Another object of the invention is to prevent oil leaking from an upstream bearing of a super" charger from entering the air compressed in the supercharger.

Another object of the invention is to decrease the cost of manufacture of supercharger blower wheels.

The invention will now be described with ref" erence to the drawing, of which:

Fig. l is a side elevation, in section, of a supercharger embodying this invention;

Fig. 2 is a side elevation, with a portion broken away, and a portion in dotted outline, of the supercharger of Fig. 1;

Fig. 3 is a sectional view along the lines 33 of Fig. 1;

Fig. i is an enlarged view, in section, of the spin vane adjusting gears of Figs. 1, 2, and 3;

Fig. 5 is a side elevation of one of the blower wheels;

Fig. 6 is a side elevation, in section, of the centrifugal fan used to remove the oil leaking from the upstream bearing of the supercharger, and

Fig. 7 is an end elevation of the fan of Fig. 6.

The supercharger has the shaft I0 to which are keyed the blower wheels ll, l2, l3, l5, l5, l6, l7, l8, l9, and 20, arranged in the order named with respect to air flow through the supercharger. As illustrated by Fig. 1, the downstream wheels have blades, the radial lengths of which decrease progressively towards the outlet 2!, whereby continuity of flow is maintained. The blades are all similar except that the downstream blades have portions removed at their tips for providing the desired reduced blade areas. The wheels all have the same number of blades.

The casing 22 around the wheels has, as illustrated by Fig. l, inner diameters which decrease downstream to correspond with the reduced wheel diameters.

The spin vanes 23 between the wheels II and I2, have the shafts 24 journalled in the casing 22, and have the gear segments 25 keyed to the shafts 24. The gear teeth in the segments 25 mesh with the gear teeth 20 of the annular gear El which is supported to rotate in a vertical plane around the casing 22 at 28. (Fig. 4.) The pinion gear 29 is attached to the shaft 30 which rotates in the bearing 3! attached by the cap screw 82 to the upper portion of the casing 22. The shaft is adapted to be rotated by a barometric or other suitable control which is not illustrated, as will be described in the following.

The shafts 24 also have attached thereto, the arms 32 with the pivot pins 33 thereon.

The spin vanes 34 between the blower wheels l2 and I3, have the shafts 35 journalled in the 4 casing 22, and have the arms 36 with the pivot pins 31 thereon, attached to the shafts 35.

The spin vanes 38 between the blower wheels [3 and M, have the shafts 39 journalled in the casing 22, and have the arms Ml with the pivot pins ll thereon, attached to the shafts 30.

The spin vanes 42 between the blower wheels H1 and I5, have the shafts 43 journalled in the casing 22, and have the arms 4% with the pivot pins 45 thereon, attached to the shafts 43.

The spin vanes 46 between the wheels l5 and 55, have the shafts 4'! journalled in the casing 22, and have the arms 48 with the pivot pins 40 thereon, attached to the shafts QT.

The spin vanes 50 between the wheels 13 and #7, have the shafts 5| journalled in the casing 2 .2, and have the arms 52 with the pivot pins 53 thereon, attached to the shafts 5!.

The spin vanes 54 between the wheels ll and it, have the shafts 55 journalled in the casing and have the arms 56 with the pivot pins 5'! thereon, attached to the shafts 55.

The spin vanes 58 between the wheels 18 and 50, have the shafts 59 journalled in the casing 22, and have the arms 60 with the pivot pins 5i thereon, attached to the shafts 59.

The spin vanes 62 between the wheels l9 and 20, have the shafts 63 journalled in the casing 22, and have the arms 64 with the pivot pins 65 thereon, attached to the shafts 63.

The levers 66 have perforations therein which end around the pivot pins 33, 31, M, 15, 50, 53, 5'3, 51 and 65 described in the foregoing, whereby rotation of the shaft 30, the pinion gear 29, the annular gear 27 and the gear segments 25, affects rotation of all of the spin vanes.

As illustrated by Fig. 1, the downstream spin vanes have radial lengths which decrease progressively towards the supercharger outlet corresponding to the decrease in the radial lengths of the blades with which they cooperate. The spin vanes have contours at different radii similar to those of the blades of the blower wheels as illustrated by Fig. 5.

The blades and spin vanes of the supercharger are preferably designed as disclosed in the H. F. Hagen application Serial No. 357,767, filed September 21, 1940, now matured into Patent No. 2,390,879 of December 11, 1945.

At sea level the spin vanes would be adjusted to provide maximum spin, all vanes being adjusted to corresponding positions. Up to 30,000 altitude, the vanes would automatically be adjusted to maintain an air pressure of 14.7 pounds per square inch in the cabin. From $0,000 to A0000 the vanes would be adjusted, if necessary,

to provide air pressures decreasing with altitude increases, from 14.7 pounds at 30,000 to 9.6 pounds at 40,000. While the supercharger could be designed to provide an air pressure of 14.7 pounds per square inch at 40,000 or even higher, the performance described was decided to be satisfactory.

The blower wheel 20 discharges the compressed air past the diffusion vanes 70 and then into the scroll outlet 2| from which a duct which is not illustrated, conveys the air into the cabin.

The upstream end of the shaft l0 has the portion 74 of reduced diameter supported for rotation in the roller bearing '52 which is supported from the casing by the stream-lined struts it. The lock-nut 16 on the upstream end of the shaft maintains same in position in the bearing l2.

The small centrifugal fan 19 having the blades 80, is attached to the shaft portion H adjacent the lock-nut 16 and acts to draw air through the passages 8| into the bearing 12, and then to move this air through the bearing and to discharge it through the opening 82 in the lower strut M to a point outside the supercharger. This air entrains the lubricating oil leaking from the bearing, and prevents it from entering the air stream passing through the supercharger.

Lubricating oil is supplied to the shaft bearings from oil cups which are not illustrated, and which would be threaded into the tapped openings 84 in the casing 22.

The downstream end of the shaft It! has the portion 85 of reduced diameter around which the roller bearing 86 is fitted. The disc 81 is attached to the shaft portion 85 against the inner race of the bearing 86, and is held in position thereagainst by the lock-nut 88 threaded onto the shaft portion 85. The plate 90 having the perforations 9| therein extends around the shaft portion 85 between the lock-nut 88 and the shaft drive coupling 92, and is supported from the inner wall 15 of the casing.

The wall 93 of the scroll outlet 2|, has the openings 94 therein which provide passages for air compressed by the supercharger against the inner side of the disc 81, providing a thrust thereagainst opposing the thrust caused by the reaction of the air passing through the supercharger. The openings 9| in the plate 90 provided an air pressure against the outer side of the disc 8! which is the same as that at the inlet of the supercharger. For example, at 40,000 altitude, the air pressure at the inlet of the supercharger and on the back side of the disc 81 will be 2.8 pounds per square inch absolute. The air pressure in the outlet of the supercharger and on the inner side of the disc will be 9.6 pounds per square inch absolute. The difference in pressure on the two sides of the disc, and its surface area, are suflicient to neutralize the thrust on the supercharger bearings caused by the reaction of the air passing through While one embodiment of the invention has been described for the purpose of illustration, it should be understood that the invention is not limited to the exact apparatus and arrangement of apparatus illustrated, as modifications thereof may be suggested by those skilled in the art without departure from the essence of the invention.

What is claimed is:

1. A supercharger comprising a rotary shaft having thereon a plurality of blower wheels, a casing around said wheels, a fan attached to the upstream end of said shaft, a bearing around said shaft between said fan and the upstream one of said wheels, means forming a chamber around said fan, means forming a passage through said bearing to the inlet of said fan, and means forming a second passage from said chamber through said casing to the exterior thereof, said fan drawing air through said first mentioned passage into said chamber and discharging the air from said chamber to the exterior of said superchanger.

2. A supercharger comprising a rotary shaft having thereon a plurality of blower wheels, a casing around said wheels, a centrifugal fan wheel attached to the upstream end of said shaft, a bearing around said shaft between said centrifugal fan wheel, and the upstream one of said blower wheels, means forming a chamber around said centrifugal fan wheel, means forming a passage from the inlet of said upstream blow-er wheel through said bearing to the inlet of said centrifugal fan wheel, and means forming a second passage from said chamber through said casing to the exterior thereof, said fan drawing air through said first mentioned passage and supplying same into said chamber and discharging the air from said chamber to the exterior of said supercharger.

HAROLD F. HAGEN.

No references cited. 

